Optical media of the write-once read-many (WORM) have been used for several years for permanently recording diverse data. Each WORM medium, usually a disk, also stores control information including a directory to the stored user or other data. It has been a usual practice to record successively in contiguous sectors or addressable areas of the disk or medium. That is, recording proceeds from a radial inward extremity, for example, toward a radial outward extremity. As the recording proceeds, all addressable areas between the radial inward extremity to the last recorded data/control are storing data. One approach to such recording is to record the non-directory data beginning at one radial extremity and record the directory beginning at a second radial extremity. In other systems, recording of directory and non-directory data proceeds from one extremity toward a second extremity.
It is desired to record data on a WORM medium wherein null or unrecorded addressable areas are interspersed with addressable areas storing data. It is also desired to operate with a WORM medium in a manner to minimize or reduce the number of addressable areas used by control information; i.e. a control of the medium, and the resulting medium, are desired to facilitate finding the last recorded data (end of the volume or EOV) as well as reducing the number of times control information is recorded, such as recording an EOV pointer and file-indicating tokens. Such tokens are alphanumeric or numeric values identifying files recorded on a medium. Such tokens are usually transparent to a computer user, i.e. the tokens are an internal mechanism of a data storing system. It is desired to reduce the number of addressable areas required for storing successively increasing values of an EOV pointer and file-indicating tokens.